1. Waves on the Ocean
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 324

2. Wavelength of a Wave l
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 324

3. Wavelength of a Wave l
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 324

4. Waves Wavelength () - length of one complete wave
Frequency () - # of waves that pass a point during a certain time period
hertz (Hz) = 1/s
Amplitude (A) - distance from the origin to the trough or crest f
Wave — a periodic oscillation that transmits energy through space
Characteristic properties of waves
1. Waves are periodic.
– They repeat regularly in both space and time.
2. Wavelength
– Distance between two corresponding points in a wave
– Symbolized by 
– Described by any appropriate unit of distance
3. Frequency of a wave
– Number of oscillations that pass a particular point in a given period of time
– Represented by the symbol 
– Units are oscillations per second or 1/s = s-1, which is called the hertz (Hz)
4. Amplitude, or vertical height, of a wave
– Defined as half the peak-to-trough height
– As the amplitude of a wave with a given frequency increases, so does its energy
– Two waves can have the same amplitude but different wavelengths
5. Speed
– Distance traveled by a wave per unit of time
– Represented by the symbol 
– Measured in meters per second (m/s)
– Speed of a wave is equal to the product of its wavelength and frequency
(wavelength) (frequency) = speed
 = 
(meters) (waves) = meters
(waves) (second) second
Courtesy Christy Johannesson

5.  A A  Waves crest greater amplitude origin (intensity) trough
greater frequency
(color)
Courtesy Christy Johannesson

6. Frequency 1 second Frequency 4 cycles/second = 4 hertz
The energy of light is closely related to its color. High energy light appears purple, low energy light appears red, and intermediate energies of light have intermediate colors such as blue, green, yellow, and orange.
Higher frequency waves have more energy and are of a shorter wavelength.
In visible light, red light has the longest wavelength (lowest frequency) and blue/violet light has the shortest wavelength (highest frequency).
12 cycles/second = 12 hertz
36 cycles/second = 36 hertz
O’Connor, Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles 1982, page 166

7. Waves Low frequency High frequency long wavelength l
Amplitude
Low
frequency
short wavelength l
Amplitude
High
frequency

8. Waves Low frequency High frequency long wavelength l
Amplitude
Low
frequency
60 photons
162 photons
low energy
short wavelength l
Amplitude
Einstein‘s photons of light were individual packets of energy that had many characteristics of particles.
• Einstein’s hypothesis that energy is concentrated in localized bundles was in sharp contrast to the classical notion that energy is spread out uniformly in a wave.
High
frequency
high energy